chapter 13

1. A "Y-shaped" protein molecule on B cells consisting of heavy and light chains, with variable regions that give the B cell its antigen-binding specificity.
5. the 10th-century practice of deliberately inoculating dried pus from smallpox pustules into a healthy person to induce immunity.
7. Conductors" of the immune system that recognize antigen via MHC II, express CD4, and activate other immune cells to fight pathogens.
8. treating a patient with antibodies against a pathogen for an immediate effect; it provides temporary immunity with no memory induction.
9. host proteins that display antigen fragments on the cell surface; this presentation is necessary for T cells to participate in the adaptive immune response.
11. a receptor on T cells consisting of alpha and beta polypeptide chains, whose variable regions form the antigen-binding site.
12. substance that can elicit a response from a B or T cell.
14. The process by which MHC molecules display antigen fragments on a cell's surface for recognition by T cells.
15. Cells: Cells that "record" information about a pathogen to fight it if it comes back.

2. the small, accessible part of an antigen that binds to an antigen receptor.
3. Cells activated B cells that actively secrete antibodies.
4. can recognize antigen via MHC I or II, express CD4 or CD8, and modulate the immune response
6. (Acquired) Immunity: A specific, slower-to-develop immune response that involves memory cells to fight a pathogen if it returns it develops when innate immunity cannot handle the pathogen.
10. that recognize antigen via MHC I, express CD8, and directly destroy cells they recognize
13. soluble form of the BCR secreted by plasma cells that binds to pathogens and marks them for elimination.